Gripper shuttle

ABSTRACT

A gripper or gripper shuttle for the insertion of weft threads which includes an assembly of elements comprising a flat beam having a spur and a flat spring which is disposed in the hollow of a plastic gripper body, the flat beam being provided with barbs to prevent the elements from coming out of the hollow.

United States Patent 1 [111 3,741,258 Svaty June 26, 1973 GRIPPER SHUTTLE 75 Inventor: Vladimir sm Liberec, [561 Remms Cited Czechoslovakia UNITED STATES PATENTS 73 Assignee: Entex zavody Textflniho 3,472,286 10/1969 Schneider 139/125 strojlremtvi Generalni reditelsmv, 3,310,072 3/1967 Strobl 139/125 Liberec, Czechoslovakia Pr mary Exqr mnerHenry S. Jatrdon Flledi p 1971 Attorney-Richard Low and Murray Schaffer 211 Appl. No.: 177,352

[57] ABSTRACT 30 F A u H P i n D A gripper or gripper shuttle for the insertion of weft I S 3:2 W an 6 7 7 threads which includes an assembly of elements comzec 0s ovakla 0 6/ 0 I prising a flat beam having a spur and a flat spring which is disposed in the hollow of a plastic gripper body, the [52] US. Cl. 139/125 flat beam bein rovided with barbs to revem the ele [51] in CI 003d 47/24 8 P p 58 Field hr Search...- 139/122 R, 125, 126, mm mm the 139/196 6 Claims, 11 Drawing Figures PATENTEDJUHZB 1975 3.141; 258

59- INVENTOR VALIMMIR svfiy BY v [MIIZORNEY GRIPPER SHUTTLE BACKGROUND OF THE INVENTION This invention relates to a gripper shuttle for the insertion of weft threads. More particularly, the invention relates to a weft shuttle of the gripper type which is guided through the shed by a system of guiding seg ments and reed dents.

Known types of grippers shuttles for weft thread insertion, particularly those with unilaterally arranged gripping mechanisms generally consist of a hollow body having at least one resilient means disposed in the hollow of the body which grips the weft thread in the course of movement of the shuttle through an intermediate lever or similar means controlled from the gripper per se. In such devices the weft thread is generally fed into the gripping mechanism by a guiding needle with or without the use of other opening means. This is normally accomplished before beginning the insertion of the weft thread into the shed.

In such devices, the resilient means, particularly when they are flat springs, are fastened in the hollow of the gripper with fasteners such as rivets, screws or simi lar means or is inserted in the hollow in a shrunken biased condition and then held there only by friction due to their subsequent expansion.

One type of known weft gripper or gripper shuttle is provided with a flat spring that is held in the hollow body by means of a stationary spur provided at one end of the body, the spring bearing against the inner side of the spur and all of which elements together constitute the gripping mechanism. Generally, a gripper of this type is guided in the course of its movement through the shed by a system of guiding segments which are arranged on the batten and by the reed dents which slide over the sliding surface of the gripper.

In a system where guiding combs are utilized, the weft shuttle is generally guided by a rib arranged on the hollow body, the rib serving also as a bumper absorbing the shock upon ejection or upon braking of the shuttle.

New developments in the field of textile materials and looms, however, have resulted in the need to modify gripper shuttle since many textile materials place different requirements on these devices. For example, the weight and surface lubrication needs of such devices have severe problems. In this regard, most known grippers are generally made of steel and when employed in weaving very fine materials, the fine reed dents which come into contact therewith are constantly ground down after relatively short periods of use and must be replaced. Consequently, attempts have been made to develop gripperswhich do not cause wearing on the reed dents. Some of these developments were aimed primarily at reducing the weight of the gripper shuttle as much as possible. This has the added advantage of reducing the force required for its acceleration, braking and the like. In addition, attempts have been made to alter the sliding surface of the shuttle by providing a surface of various plastics having a low coefficient of friction cemented to the body. However, these attempts at improving shuttles have not proved to be entirely satisfactory in actual use since they do not eliminate the weight problem and, still result in undesired damage to the reed element. They also present difficulties in manufacturing.

There exists, therefore, a need for gripper shuttles which do not exhibit the stated disadvantages.

It is a primary object of this invention to provide a shuttle which exhibits satisfactory operating qualities.

It is another object of the invention to provide a gripper shuttle which is light in weight.

It is another object of the invention to provide a shuttle which does not damage the reed dents.

It is still a further object of the invention to provide a shuttle which readily lends itself to relatively simple manufacturing.

It is still a further object of the invention to provide a gripper shuttle which is light in weight but structurally firmer than those known and which has a surface exhibiting a low friction coefficient.

It is still another object of the invention to provide a shuttle having an element comprising a flat beam including a spur and a flat spring attached thereto inserted in the hollow of a plastic body, the flat beam being provided with reverse tips to prevent the element from coming out of the hollow of the body.

Numerous other objects and advantages of the invention will be apparent from the following description thereof which is to be taken in conjunction with the accompanying drawings.

THE DRAWINGS FIG. 1 is a plan view of a gripper according to the invention;

FIG. 2 is an elevational view of the gripper shown in FIG. 1;

FIG. 3 is a plan view of the body of the device shown in FIG. 1;

FIG. 3a is a sectional view of the body shown in FIG. 3 and taken from the rear;

FIG. 4' is a view in elevation and partially in section of the body shown in FIG. 3;

FIG. 5 is a view in perspective of the elements inserted in the body hollow, including the flat beam provided with a spur and the flat spring affixed thereto;

FIG. 6 is a sectional view in elevation of alternative embodiment of a gripper according to the invention showing in detail the disposition of the elements inserted in the body hollow and a variation of the arrangement of the relationship for affixing the flat beam and flat spring to each other;

FIG. 7 is a plan view of the elements shown in FIG. 6 which are inserted in the body hollow;

FIG. 8 is a view in perspective of the elements shown in FIG. 7;

FIG. 9 is a view in elevation of the elements to be inserted in the body hollow in a one-piece configuration; and

FIG. 10 is a plan view of the one-piece element shown in FIG. 9.

SUMMARY OF THE INVENTION A gripper or gripper inserter in accordance with the invention comprising a plastic body having a hollow portion and elements including a flat beam provided with a spur and reverse tips and having a flat spring fixed thereto, all of which are disposed in the body hollow.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now more particularly to FIG. I, a gripper in accordance with the invention comprises a body I made of light weight, structurally firm, non-metallic or plastic, material. The body may be simply moulded in one piece of any suitable plastic which provides a surface having a low coefficient of friction such as, for example, DELRIN. The body is provided with a closed tip 2 and a longitudinal hollow 3 in boatlike fashion. The hollow has a cross-section in the form of a flat T as shown more precisely in FIG. 3a. The body is also provided with a sliding upper surface 4 which slides on the dents of a reed of a loom in a conventional manner. The body also has a rib 5 along its lower surface which guides it through the shed in cooperation with guiding segments mounted on a conventional batten.

Inserted in the hollow 3 of the body is an assembly of elements generally made of metal such as steel including a flat beam 6 provided with a vertical spur 7 and a flat spring 8 fixed to the beam by connecting elements 9, such as rivets or other suitable fastening means at the end opposite the spur, as illustrated more fully in FIG. 5. A flat member 10 is fixedly interposed between the beam 6 and the spring 8 so that the spring can be moved or deviated when inserting a weft thread (not shown) between the spur 7 and the free end 11 of the flat spring. Member 10 also allows adjustment of the space between flat spring and flat beam so'that, when assembled, the whole unit snugly fits into and fills the front part of the hollow 3 of the body as shown in FIG 6.

The assembled elements are secured, after insertion in the hollow 3, by providing reverse tips or barbs 12 located on both lateral edges of the beam 6. The barbs 12 press against the inner walls of the body 1. Insertion of the assembled elements into the hollow of the barbs is possible since, being made of plastic, the body is somewhat elastic. On the other hand, removal from the hollow requires force and cannot be done without seriously damaging the body. In view of the negligible cost of the plastic body, damage to the body on removing the assembly from the hollow is not serious, and it can be easily replaced. If desirable, the assembly can also be fixed in the hollow with fasteners such as screws, rivets and similar means (not shown).

An alternative embodiment of the gripper of this invention involves modification of the beam, spring and spur as shown more particularly in FIGS. 7 and 8 at the point where the spring contacts the spur of the beam.

At the free end 11 of the beam 8 there is provided a recess 13 through which the spur 7 passes, the spur 7 being bent in such a manner that the point of gripping for the weft thread is at the extreme rear end of the device between the free end of the spring and the spur.

to form an integral flat beam and spring in the form of a hairpin. This embodiment reduces still further the overall weight of a gripper in accordance with the invention.

The gripper of this invention presents many advantages. The light weight, structurally strong plastic body having surfaces exhibiting a low coefficient of friction is easily manufactured by known plastic moulding processes and does not readily damage the reed dents of looms on which it is employed. In addition, it is relatively inexpensive to make and the assembly of elements to be inserted in the hollow of the body can be easily placed therein without the use of additional fastening means and removed therefrom for use in replacement bodies of plastic.

In addition, variations in the structure of the internal components result in weight reduction and considerable reduction of weft thread wastage. Numerous other advantages of the invention will be apparent to those skilled in the art.

It is to be understood that many modifications of the embodiments of this invention may be made without departing from the spirit and scope thereof. Therefore, the invention is not to be limited to the described embodiments thereof except as defined in the appended claims. v i

What is claimed: I

l. A gripper shuttle for the insertion of weft threads in a loom comprising a plastic body having a longitudinal hollow therein and a thread holding assembly inserted within said hollow said assembly comprising a flat beam provided with a spur at one end, a flat spring fixed to said beam at the end opposite said spur,extending therealong and spaced in part from said beam, said spur and the open end of said spring forming a gripping surface for weft threads to be guided through the shed of said weaving loom, the spring being resiliently movable with respect to said beam to permit said spring to separate from said spur to permit entry of a thread therein.

2. The gripper according to claim 1 including means for securing said beam to the body.

3. The gripper according to claim 2 wherein said securing means comprises a plurality of barbs arranged along the edges of said beam, said barbs being engageable with the plastic body.

cross sectional configuration.

i i i t t 

1. A gripper shuttle for the insertion of weft threads in a loom comprising a plastic body having a longitudinal hollow therein and a thread holding assembly inserted within said hollow said assembly comprising a flat beam provided with a spur at one end, a flat spring fixed to said beam at the end opposite said spur, extending therealong and spaced in part from said beam, said spur and the open end of said spring forming a gripping surface for weft threads to be guided through the shed of said weaving loom, the spring being resiliently movable with respect to said beam to permit said spring to separate from said spur to permit entry of a thread therein.
 2. The gripper according to claim 1 including means for securing said beam to the body.
 3. The gripper according to claim 2 wherein said securing means comprises a plurality of barbs arranged along the edges of said beam, said barbs being engageable with the plastic body.
 4. A gripper as defined in claim 1 wherein the spring is provided with a recess at the free end and the spur passes through said recess.
 5. A gripper as defined in claim 1 wherein the beam and the spring are in an integral assembly having the shape of a hairpin.
 6. A gripper as defined in claim 1 wherein the longitudinal hollow of the plastic body has a flat T-shaped cross sectional configuration. 